Potential Mesa Reissues? IIC+ and Dual Rec

[MirrorProfiles]

Fair enough. Then what’s your theory on why some amps don’t exhibit the symptoms? Natural variation in other components in the circuit? I suppose that’s possible.

The IIC+ in its original form is a borderline unstable circuit. There’s some weird inductance behavior that IIRC is attributed to the circuit boards - I’d need to dig for specifics. Perhaps something changed in this new layout and that formerly controlled behavior is getting amplified.

I think it’s this, and needing particularly quiet and well behaving valves. I’ve had oscillation from a few high gain amps with it that has been down for the preamp tubes. My Mark III is often on the edge of oscillation, it doesn’t take much to tip it over.

It’s not really a matter of how much gain the amp has, so much as how hard each gain stage is working. Something like an EVH has way more gain stages but they’re working a lot less hard. Add in some dodgy PCB’s and crosstalk and things can get unstable pretty quickly.

I wouldn’t be surprised if a better PCB design might have helped somewhat, but it really depends if the oscillation is a common problem are just the result of a dud batch of valves.

 

[nicolasrivera]

Holy shit, buy a lotto ticket, because I actually agree with Nicolas.

Best Xmas ever!! thanks bud.

 

[LCW]

Fair enough. Then what’s your theory on why some amps don’t exhibit the symptoms? Natural variation in other components in the circuit? I suppose that’s possible.

The IIC+ in its original form is a borderline unstable circuit. There’s some weird inductance behavior that IIRC is attributed to the circuit boards - I’d need to dig for specifics. Perhaps something changed in this new layout and that formerly controlled behavior is getting amplified.

After watching that video I can repeat it with my IIC+ RI.

HOWEVER - that’s with cranking the Lead Master to 7 or above. I don’t know who in their right mind would have it that high to be honest.

Here’s my home settings right now and it’s as quiet as you’d expect a high gain amp to be (other than feedback if standing I’m within 2 ft and facing it).

For example with the Master at about 1 1/4 and Lead Master at 2, and the rest as shown in the pic below, I’m at like 93 db standing 4-5 ft from the amp.

So frankly for me it’s moot. As I’ll never be at the settings that cause the squeal condition. And if I am, it’s because I’m playing stadiums un-mic’d.

 

[spawnofthesith]

RE cranking the lead master to ridiculous levels (several folks quoted me): I can’t think of a logical reason to run the lead master at 8 period. I guess if you’re treating it as a single channel amp you could set it up that way. There’s no circumstance where you’d be getting a remotely balanced volume differential like that though, unless you were also running the overall master at stupid levels as well. And these aren’t old Marshall’s, shit stops sounding good past a certain threshold on power amp volume settings

 

[Elf]

So basically the theory is that he was doing this?

 

[James Freeman]

What's the issue, the reissue oscillates more than the og with the same settings?

 

[Humbug]

The IIC+ in its original form is a borderline unstable circuit. There’s some weird inductance behavior that IIRC is attributed to the circuit boards - I’d need to dig for specifics. Perhaps something changed in this new layout and that formerly controlled behavior is getting amplified.

Someone in Mesa's offices probably used the old Post-it note with "IIC+: bend component X 2mm away from component Y if oscillation" as a rolling paper.

 

[EOengineer]

Someone in Mesa's offices probably used the old Post-it note with "IIC+: bend component x 2mm away from component y if oscillation" as a rolling paper.

That may or may not have been me.

 

[laxu]

What's the issue, the reissue oscillates more than the og with the same settings?

As I understand it, that the amp starts oscillating at fairly normal settings. Lead master on 5 should be well within reason, like rather loud but not absolutely cranked.

I don't think it matters what the OG does, we are talking about a new amp here. Doesn't matter if it's a reissue, it should not have this sort of problem.

 

[norminal]

Nothing like a good “[insert product or issue name here]-gate” to bring in the new year.

Play Authentic™

 

[paisleywookiee]

So basically the theory is that he was doing this?

View attachment 34994

“And I would have gotten away with it too, if it weren’t for you meddling kids!”

 

[HomespunEffects]

This oscillation issue is IMO more telling of the state of our current production preamp tubes than anything else. It’s an extremely high gain amp and I think a lot of people are encountering one or more microphonic tubes.

Yeah, my Mark Five:35 had an oscillation issue as well. I’m thinking that it was simply a microphonic tube.



I never really diagnosed it as it only happened on very high gain settings. That ain’t my thing.

 

[nightlight]

Sigh, this is always a losing battle, but again, here is Ola playing the Mooer Black Truck.



Sounds like every Ola demo, right?

Sad thing is, I doubt that thing sounds anything like that. Mainly because I've heard other demos.

Anyhow, here is Ola's full demo of the IIC+ RI.




Which brings us back to the question: does the amp oscillate at higher master settings?

A master volume at 2 or 3 is really low. I hear string noise in my room at those volumes.

Is the amp usable at higher volumes? Or do you have to keep the master volume of a 100-watt amp at maybe 20 watts to prevent squealing?

Which is what everyone really should want to know. I don't want to pay $3.6k for something that squeals like that.

I had a Victory Kraken that did the same thing and I reported it on multiple forums.

 

[nightlight]

RE cranking the lead master to ridiculous levels (several folks quoted me): I can’t think of a logical reason to run the lead master at 8 period. I guess if you’re treating it as a single channel amp you could set it up that way. There’s no circumstance where you’d be getting a remotely balanced volume differential like that though, unless you were also running the overall master at stupid levels as well. And these aren’t old Marshall’s, shit stops sounding good past a certain threshold on power amp volume settings

At master volumes of 2 or 3, I can hear my strings in the room.

Surely you're not saying that no one needs a 100-watt amp to put out 100 watts. That's a ridiculous argument.

 

[spawnofthesith]

At master volumes of 2 or 3, I can hear my strings in the room.

Surely you're not saying that no one needs a 100-watt amp to put out 100 watts. That's a ridiculous argument.

What older marks do you have ? No one’s hearing string noise with the master on 3 on any IV or III I own or have owned

A Mark IV at 3 on the master output is approaching drown out even the loudest of drummers, and it’s not like it keeps getting much louder after a certain point. You’re just getting more (and imo harsh sounding) compression

But the lead master on the IIs and IIIs is different anyways, it’s not independent from the master volume they are in conjunction with each other. The lead master is primarily there to balance the volume with the other channel

The overall master is the primary juice. If that’s off you aren’t getting any volume on the lead channel no matter how high you run the lead master. Again I can’t think of any practical or logical reason to have the lead master at 8 unless you had the regular master almost off for some reason. On my III I only run the the lead master a notch or two higher than wherever the master is set at most

Past 3 things are deafening and the increase in volume up the knob becomes more and more negligible. I’ve gone as high as 5 with the band on the master volume (and my current III is only 60 watts) but its not much louder than a couple clicks below, it just sounds worse

 

[EOengineer]

What older marks do you have ? No one’s hearing string noise with the master on 3 on any IV or III I own or have owned

A Mark IV at 3 on the master output is approaching drown out even the loudest of drummers, and it’s not like it keeps getting much louder after a certain point. You’re just getting more (and imo harsh sounding) compression

But the lead master on the IIs and IIIs is different anyways, it’s not independent from the master volume they are in conjunction with each other. The lead master is primarily there to balance the volume with the other channel

The overall master is the primary juice. If that’s off you aren’t getting any volume on the lead channel no matter how high you run the lead master. Again I can’t think of any practical or logical reason to have the lead master at 8 unless you had the regular master almost off for some reason. On my III I only run the the lead master a notch or two higher than wherever the master is set at most

Past 3 things are deafening and the increase in volume up the knob becomes more and more negligible. I’ve gone as high as 5 with the band on the master volume (and my current III is only 60 watts) but its not much louder than a couple clicks below, it just sounds worse

This is my experience as well. Last time I had my Mark III master at 3 it evaporated a guy walking his dog by my house. Just gone. Dog was fine though.

 

[la szum]

How does anyone ever truly know what an amp sounds like isolated? I feel like
all of those "Amp only demos" are deceptive as F. Weren't guitar amps made for
bands and an actual full mix of other instruments. Duh? Context!

I say this, because pretty much every guitarist I have met in person and talked
to understands that what we dial in with our ears in isolation often needs to be
tweaked (bass lowered, gain rolled back, and mids bumped) to sound even
remotely decent in the context of a full band.

Simply put, the massive tones we think sound big as fuck in isolation are some
of the worst you can take to the stage or the studio.

 

[JiveTurkey]

Master volume on 8-9 on a 100 watt amp howls when you're standing in front of it?

 

[paisleywookiee]

At master volumes of 2 or 3, I can hear my strings in the room.

Maybe on one of those desktop Katana amps. You're not going to hear your strings at 2-3 on any Mark, even the 25w.

 

[spawnofthesith]

Even with an attenuator i can’t hear my strings on a mark at 3